Figure 3
Malignant melanoma (or metastasizing Spitz tumor?) of a 7-year-old boy with lesion from the left back initially diagnosed as atypical Spitz nevus at an another institution. The tumor measures 9 mm in diameter and at least 4.4 mm in Breslow thickness. Other attributes: asymmetry, reasonable circumscription, no ulceration, no pagetoid melanocytosis, no maturation, high cellular density and confluence of melanocytes throughout dermis, 9/mm2 mitotic rate, deep mitoses, and prominent cytological atypia. The lesion recurred in a matter of months and two SLNs contained large deposits of an atypical melanocytic tumor. Long-term follow-up will be needed to determine whether there is disease progression or not. (a) Scanning magnification shows a large raised polypoid tumor with slight asymmetry. (b) The superficial portion of the tumor is characterized by confluent sheets of melanocytes replacing dermis. (c) Note striking density of melanocytes at base with cytological atypia. Many nuclei contain prominent nucleoli. (d) SLN containing large tumoral deposit replacing large part of node. Note pronounced cytological atypia of spindled melanocytes.
